A multi-output electronic ballast is disclosed. The multi-output electronic ballast is used to drive a plurality of lamp assemblies and includes an AC/DC converter, a first inverter, a second inverter, an auxiliary voltage generator, and a control circuit. The AC/DC converter converts an AC input voltage to a high DC voltage. The first inverter converts the high DC input voltage to a first AC voltage selectively. The second inverter converts the high DC voltage to a second AC voltage. The auxiliary voltage generator generates an auxiliary voltage. The control circuit receives the auxiliary voltage generating circuit and outputs a control signal to the first inverter according to the switching operation of a first external switch. When the control signal is transmitted to the first inverter, the first inverter comes into operation and converts the high DC voltage to the first AC voltage.